I wondered when the anti-rabies quarantine rules for pets and other animals was brought in?

The BBC story about the relaxing of the regulations in 2011 says:

"Dogs entering the UK have been subject to the quarantine since 1897. Cats were added in 1928, and ferrets in 2004".

Surely a random kitten picked up at sea with no papers and provenance should have been locked away before it could set a paw on land and if they had tried to smuggle it in and been caught, the Walkers would have been heavily fined. Of course that would have meant Sinbad being unavailable for Bridget luring duties in Secret Water.